Solving atmospheric and vacuum distillation problems
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“In the “two-stage condensation” process, the reflux temperature is higher than that in the “one-stage condensation” process, and the reflux ratio is greater as well; this is beneficial for the fractionation of the product at the top of the tower. I don’t understand what’s being said; please help!
https://bbs.hcbbs.com/thread-410755-1-1.html It is recommended that the original poster read this book carefully; then the answers will become clear!
Read more technical Q&A on atmospheric and vacuum distillation units
Read more technical Q&A on atmospheric and vacuum distillation units
Control the reflux flow rate based on the distillation temperatures of each side stream
Two-stage condensation: The vapor at the top of the tower undergoes partial condensation once before entering the reflux tank; after another round of condensation, it enters the product tank. The reflux used for tower top reflux is taken from the reflux tank; the temperature of this reflux oil corresponds to the bubble point temperature of the oil. A higher reflux temperature requires a larger amount of reflux in order to balance the heat at the tower top, hence the reflux ratio is relatively higher compared to that in a section with condensation. Advantages: Saves investment in cooling and exchange equipment; backflow has little impact on product separation accuracy ； Disadvantage: Complex process
I think the simple explanation is that the further down the petroleum distillation range, the higher the temperature; therefore, the temperature for secondary condensation is high. I’m not sure if this simple understanding is correct